Abstract Among the 2.1 million adolescents aged 10-19 living with HIV in 2012, 82% were in sub-Saharan Africa, and among these, 58% were girls. In sub-Saharan Africa, women?s HIV risk is linked with their experiences of intimate partner violence (IPV). Adolescence is a key time to target social norms linked to HIV and IPV because adolescents are forming ideas about normative behavior and their first sexual relationships during this time. A recent systematic review of HIV prevention interventions for young people in sub-Saharan Africa found that few interventions were effective in part because social norms for sexual behavior were overlooked. One intervention approach that has been successful in targeting norms and sustaining changes for HIV-related behaviors is to intervene with social networks. Network interventions often leverage central, trusted, and/or popular network members to deliver risk reduction messages to their known network contacts, thereby diffusing health promoting norms to people in their immediate social environment. The level of cohesion within networks may also amplify the effect of peer norms on behaviors. However, network interventions have not yet been fielded with adolescent girls in sub-Saharan Africa. Working with networks might also be strategic for reaching adolescent girls who are not in school, an increasingly important population to curbing the HIV epidemic globally. Two key first steps to a network HIV and IPV prevention intervention approach with adolescent girls are: identifying the networks of adolescent girls; and understanding how networks influence adolescent girls? HIV and IPV related behaviors. Our team, with funding from NIMH, has successfully located social networks of young men at risk for HIV in Dar es Salaam, Tanzania; we propose using a similar strategy to identify networks of adolescent girls in one ward (equivalent to a US census tract) of Dar es Salaam. Our aims are to: (1) Identify venue-based social networks of adolescent girls, aged 15-19, in Dar es Salaam using the rigorous PLACE methodology, involving community informant interviews and mapping; characterize 15-20 networks (density and centralization, etc.) by conducting surveys with all adolescent girls in 15-20 networks and in-depth interviews with key informants; and describe associations between network characteristics, norms and behaviors related to HIV and IPV. (2) Assess the acceptability of a network approach that seeks to change norms for HIV risk behaviors and IPV, while enhancing cohesion within girls? networks, by piloting approaches, messages and communication channels with girls. This proposal is lead by an early-stage investigator with expertise in youth networks in Dar es Salaam. The proposal is responsive to RFA-MH-17-555 by developing a social network intervention to alter adolescent girls? HIV and IPV related norms and behaviors. Reaching adolescent girls through their networks may prove strategic for implementing a variety of HIV prevention strategies.